1. Field of the Invention
The present invention relates to a working vehicle in which a drive unit is arranged at a rear position of a traveling vehicle body. More specifically, the present invention relates to a configuration supporting the drive unit.
2. Description of Related Art
As a configuration supporting a drive unit in a working vehicle, Related Art 1 discloses a configuration in which a vehicle body frame is configured to include a pair of left and right upper pipes and a pair of left and right lower pipes; a bottom portion of a drive unit (referred to as an “engine unit” in Related Art 1), which is configured from an engine and a transmission, is supported in an anti-vibration manner on the lower pipes by a lower engine mount; and an upper portion of the engine of the drive unit is supported in an anti-vibration manner on one of the upper pipes by an upper engine mount.
In the configuration of Related Art 1, the lower portion of the drive unit is supported in an anti-vibration manner on the lower frame, and the upper portion of the drive unit is supported in an anti-vibration manner on the lower frame. Thereby, even when traveling on rough terrain and the like, a phenomenon is inhibited in which the drive unit vibrates greatly, and disadvantageous large displacement of the upper portion of the engine in jump landing, sharp cornering, and sudden acceleration is inhibited.
[Related Art 1] Japanese Patent Laid-Open Publication No. 2006-27466
As a drive unit provided in a working vehicle, an engine, a transmission case, a continuously variable transmission, and the like are possible examples, and these are heavy. Further, it is desirable that the drive unit be supported on the vehicle body frame in a vibration inhibited state and without large displacement.
In response to such demand, as disclosed in Related Art 1, the lower portion of the drive unit is supported on a lower structure of the vehicle body frame, and the upper portion of the drive unit is supported on an upper structure of the vehicle body frame. In such a configuration, large displacement of the drive unit can be inhibited.
However, in order to support a relatively large drive unit, such as that in a working vehicle, on a frame, as disclosed in Related Art 1, the upper portion of the drive unit is supported on one of the pair of left and right upper pipes that constitute the vehicle body frame. In such a configuration, a side of the drive unit that corresponds to the other one of the upper pipes is allowed to be displaced, and thus the drive unit may easily become unstable. Therefore, there is room for improvement.
In particular, in the configuration in which the vehicle body frame is provided with a pair of left and right underframes, and a distance between the pair of left and right underframes in a lateral direction is short, even when the two sides of the bottom portion of the drive unit are supported on the underframes by mounts, a distance between the left and right mounts is short, and thus, it is difficult to inhibit vibration of the upper portion of the drive unit in the lateral direction. Therefore, there is room for improvement also with regard to this point.